peribulbar anaesthesia in eye surgery (4)

PERIBULBAR BLOCK AND GLOBE PERFORATION

Dr. Saptarshi Dasgupta .(MD)Consultant Anaesthesiologist

Recent experience of globe perforation

• PLAN : PE + IOL UNDER LA

• ANAESTHESIA– PERIBULBAR ( SITES - IT & SN)

• COMPLICATION – GLOBE RUPTURE WITH IRIS PROLAPSE & PARTIAL NUCLEUS PROLAPSE

PERIBULBAR ANAESTHESIA

Objectives of anaesthesia in intraocular surgery

• Akinesia of globe and lids• Anaesthesia of globe and lids and adnexa• Control of intraocular pressure• Control of systemic blood pressure• Relaxation of patient• Absence of untoward reactions• Smooth emergence• Adequate post-operative analgesia

ANATOMY

Anatomy

• Orbit – shape of irregular pyramid– Base at front– Axis points posterio-medially towards skull

• Globe lies in anterior part of orbit - sits high and lateral

Anatomy

• Four rectus muscles arise from the back of orbit

• Insert into the globe just forward of equator• Form a cone - boundary between two compartments

Techniques of peribulbar block

Techniques of peribulbar block

• 5 ml bupivacaine 0.5% and 5 ml lignocaine 2%.• 1500 units of hyaluronidase (mixed to aid

diffusion within the orbital tissue) are drawn into a 10 ml syringe. Superior & inferior

injections of 5 ml each are given with an 1 inch, 23-G Steel needle or ½ inch,26-G

needle. Inferior injection is given at the junction of the outer one

third & inner two third of the lower orbital rim.

Techniques of peribulbar block

• Superior injection is given usually nasally just above the medial canthus . The superior injection may be avoided till the time the inferior injection takes effect (3-5 min), to judge the necessity for the additional

injection.

Techniques of peribulbar block

• If good akinesia is attained by the inferior injection, there is no need for the superior injection. Gently press on the lower lid between

the orbital margin and the globe to feel the inferior orbital notch and with the other

hand progressively inject 5 ml of anesthetic solution starting just under the skin,

progressively to just behind the equator of the globe.

Sites

• INFEROTEMPORAL• SUPERONASAL• MEDIAL

Position Of Eyeball• lower outer corner of the orbit at a point on a line drawn vertically down from the outer canthus to the infraorbital margin

•23 gauge needle no longer than 1 inch is directed paralleling the wall of the orbit with the patient's gaze in the primary position.

Guiding Of Needle

• The needle should be slowly advanced, stopping immediately – if there is either a tugging movement of the globe,

which may indicate snagging of the needle on sclera or an extraocular muscle (EOM), or

– Some ask the patient to look up and down to ensure that the globe has not been impaled.[21] Others believe that this could cause adjacent orbital structures to be lacerated over the needle tip.

– if there is either severe pain or resistance to injection, either of which can indicate injection into the globe.

Type Of Needle

BLUNT NEEDLE • LESS CHANCES OF

PERFORATION

• MORE DAMAGE IF PERFORATION

SHARP NEEDLE• MORE CHANCES OF

PERFORATION

• LESS DAMAGE

Complications of Peribulbar Block

Either from the agents used Or The block technique itself

Complications • Venous orbital hemorrhage . • Arterial orbital hemorrhage. • Oculocardiac incidence• Allergic reaction• Ophthalmoplegia - direct damage to the EOM or

its nerve. • Globe perforation • Central spread of anesthetic - Life-threatening

complications can result from intrathecal spread.• Optic nerve damage.

Globe perforation

• This complication is very rare in experienced hands. • More common with longer eyes specifically with

staphyloma• If the needle catches the sclera, the cornea first moves

toward the needle and then suddenly away from it as the needle passes through the sclera.

• It is often painful, but not always noticed at the time. • surgeon might notice the absence of the red reflex, an

excessively soft eye or an excessively hard eye with cloudy cornea if LA has been injected inside the eye.

Globe perforation

• Sometimes, the procedure is uneventful and the telltale retinal appearance may be noticed years later on routine fundoscopy.

• Rarely, enough LA can be injected inside the eye to cause ocular explosion. This requires IOPs of 2800-6400 mmHg.[21]

• Even with immediate recognition, the visual prognosis for such an eye is poor.

How to avoid Perforation ?

• Subtenon’s Block can be used as an alternative to Peribulbar Block as incidence of perforation is minimal.

RISK & SEQUELAE OF SCLERAL PERFORATION DURING PBA

• A retrospective study of receiving 2ndary care for complications of globe perforation, over 17 yrs period.

• Results- this review identified 9 such among them 2 were minor, rest required one or more vitrectomies for RD.

• 2 of the 9 regained reading ability, one eye maintained no light perception & 6 eyes had ambulatory vision only.

THANK YOU !!